Fig. 3.

PHF6 domain is involved in tau oligomer formation and cell death induced by tau overexpression. (A) Schematic representation of PHF6* and PHF6 domains in tau protein. (B) Tau oligomer expression by WT and ΔPHF6 tau overexpression was detected by immunofluorescence using T22 tau oligomer antibody. 4R tau antibody was used as an expression control because 4R tau is expressed from exogenous tau but not from endogenous tau. Neurons were treated with lentivirus (MOI 10) and fixed on day 5 after tau overexpression. The PHF6 deletion reduced T22 signals but not RD4 signals in the neurites of the infected neurons. (−): lentivirus-untreated group. Scale bars, 100 µm. (C) Cell viability of iPSC-derived neurons at 5 days after WT or ΔPHF6 tau-overexpression (n = 3, mean + SD). ***: P ≤ 0.001 by analysis of covariance, WT vs. ΔPHF6.